Method and apparatus for treating bone fractures, and/or for fortifying and/or augmenting bone, including the provision and use of composite implants

Abstract

A composite implant comprising an injectable matrix material which is flowable and settable, and at least one reinforcing element for integration with the injectable matrix material, the at least one reinforcing element adding sufficient strength to the injectable matrix material such that when the composite implant is disposed in a cavity in a bone, the composite implant supports the bone. A method for treating a bone, the method comprising: selecting at least one reinforcing element to be combined with an injectable matrix material so as to together form a composite implant capable of supporting the bone; positioning the at least one reinforcing element in a cavity in the bone; flowing the injectable matrix material into the cavity in the bone so that the injectable matrix material interfaces with the at least one reinforcing element; and transforming the injectable matrix material from a flowable state to a non-flowable state so as to establish a static structure for the composite implant, such that the composite implant supports the adjacent bone.

What is claimed is: 
     
       1. A composite implant for locating in an opening of a bone comprising:
 a degradable matrix material including a degradable polymer; and 
 more than one reinforcing elements disposed within the degradable matrix material, the at least one reinforcing element being degradable and adding sufficient strength to the matrix material such that when the composite implant is capable of supporting and stabilizing the bone when implanted and will degrade over time; 
 the reinforcing elements comprise: 
 a flexible rod including fibers having a twist configuration formed of degradable filaments, and a degradable material which binds the degradable filaments together in fixed relation to one another; 
 wherein the reinforcing elements are held together by a wound connecting structure; 
 wherein the composite implant is in the form of an elongated structure. 
 
     
     
       2. A composite implant according to  claim 1  wherein the degradable polymer comprises a polymer or copolymer of lactide, L-lactide, D-lactide, DL-lactide, polylactide, poly-L-lactide (PLLA), poly-D-lactide (PDLA), poly-DL-lactide(PDLLA), glycolide, caprolactone, polyhydroxybutyrates (PHB), polyhydroxyalkanoates, polyurethane, or polyesters. 
     
     
       3. A composite implant according to  claim 2  wherein the degradable polymer comprises a copolymer of L-lactide. 
     
     
       4. A composite implant according to  claim 1  wherein the at least one reinforcement element comprises at least one from the group consisting of a soluble phosphate glass, a resorbable phosphate glass, a soluble borate glass, a resorbable borate glass, a soluble silicate glass, and a resorbable silicate glass. 
     
     
       5. A composite implant according to  claim 4  wherein the at least one reinforcement element comprises at least one inorganic ion selected from the group consisting of Fe, Ca, Sr, Zn, B, K, Mn, and Ce. 
     
     
       6. A composite implant according to  claim 4  wherein the at least one reinforcement element comprises silicate glass fibers. 
     
     
       7. A composite implant according to  claim 1 , wherein the implant has an outer region configured to control the ingress of body fluids through the outer region and into an interior of the composite implant, wherein the outer region comprises at least one layer. 
     
     
       8. A composite implant according to  claim 7  wherein the outer region comprises a plurality of layers, and further wherein the plurality of layers are formed by different materials. 
     
     
       9. A composite implant according to  claim 7 , wherein the at least one layer is configured to provide a desired porosity. 
     
     
       10. A composite implant according to  claim 7 , wherein the outer region comprises pores configured to allow bone ingrowth. 
     
     
       11. A composite implant according to  claim 9  wherein the porosity is varied across the extent of the at least one layer so as to provide regions of greater or lesser porosity. 
     
     
       12. A composite implant according to  claim 9 , wherein the outer region comprises a compatibilizer. 
     
     
       13. A composite implant according to  claim 9 , wherein the outer region of the composite implant comprises a degradable material. 
     
     
       14. A composite implant according to  claim 13  wherein the degradable material of the outer region comprises a stereoisomer, polymer or copolymer of lactide, L-lactide, D-lactide, DL-lactide, polylactide, poly-L-lactide (PLLA), poly-D-lactide (PDLA), poly-DL-lactide(PDLLA), glycolide, and caprolactone. 
     
     
       15. A composite implant according to  claim 9 , wherein the outer region comprises an inorganic filler, optionally wherein the outer region comprises an organic filler. 
     
     
       16. A composite implant according to  claim 15  wherein the inorganic filler includes an orthophosphate, a monocalcium phosphate, a dicalcium phosphate, a tricalcium phosphate, a tetracalcium phosphate, an amorphous calcium phosphate, or a biodegradable/bioresorbable glass. 
     
     
       17. A composite implant according to  claim 15  wherein the inorganic filler comprises a particulate or a short fiber. 
     
     
       18. A composite implant according to  claim 17 , wherein the inorganic filler has a mean diameter in the range of from 10 microns to 500 microns. 
     
     
       19. A composite implant according to  claim 17 , wherein the filler has a mean diameter in the range of from 1 nm to 100 microns. 
     
     
       20. A composite implant according to  claim 15  wherein the outer region of the composite implant comprises a degradable material, and further wherein the inorganic filler ranges from 10 wt % to 50 wt % of the degradable material. 
     
     
       21. A composite implant according to  claim 15  wherein the outer region of the composite implant comprises a degradable material, and further wherein the inorganic filler is over 50 wt % of the degradable material. 
     
     
       22. A composite implant according to  claim 15  wherein the filler is selected so as to provide the composite implant with a desired porosity, a bone ingrowth surface, and pore connectivity. 
     
     
       23. A composite implant according to  claim 1  wherein a cross-sectional profile of the composite implant comprises one from the group consisting of 3-sided, 4-sided, 6-sided, 8-sided, cruciform, and multi-lobed. 
     
     
       24. A composite implant according to  claim 9 , wherein the outer region provides surface features. 
     
     
       25. A composite implant according to  claim 24  wherein the surface features comprise threads. 
     
     
       26. A composite implant according to  claim 9 , wherein the composite implant is in the form of one selected from the group consisting of a pin, a bent pin, a semi-elastic pin, a screw, a nail, an anchor, a toggling bone anchor, and a mechanical fastener. 
     
     
       27. A composite implant according to  claim 9 , wherein the outer region of the composite implant comprises a coating. 
     
     
       28. The composite implant of  claim 1 , wherein the wound connecting structure includes a textile. 
     
     
       29. The composite implant of  claim 1 , wherein the degradable matrix material and the degradable material are different. 
     
     
       30. The composite implant of  claim 1 , wherein the fibers of the flexible rod have a same axial direction. 
     
     
       31. The composite implant of  claim 30 , wherein the flexible rod includes fibers having different twist configuration. 
     
     
       32. An article for locating in an opening of a bone, the article being a pin or screw, and comprising:
 a plurality of axial reinforcement elements disposed in a degradable matrix material, 
 a wound connecting structure holding the axial reinforcement elements together, and one or more layers of an outer region around the wound connecting structure; 
 wherein the screw or pin has an axial direction along its length, 
 wherein the axial reinforcement elements comprises a flexible rod including fibers oriented in the axial direction extending from a first end region of the pin or screw to an opposing end region, 
 wherein the fibers of the axial reinforcement elements include filaments formed of a degradable glass bound together by degradable material, 
 wherein the degradable matrix material includes a thermoplastic polymer, 
 wherein the wound connecting structure includes fibers formed of a degradable glass, and 
 wherein the pin or screw has a porous surface; 
 the axial reinforcement element has a modulus of 6 GPa to 90 GPa and is included in an amount of 10 volume percent to 75 volume percent of the pin or screw. 
 
     
     
       33. The article of  claim 32 ,
 wherein the pin or screw is a screw having a threaded outer surface; 
 wherein the degradable matrix material includes a copolymer of L-lactide; 
 the fibers in the rod includes fibers having different twist configurations; 
 wherein the screw is canulated; and 
 wherein the wound connecting structure includes bias fiber bundles. 
 
     
     
       34. A pin for locating in an opening of a bone comprising:
 one or more axial reinforcement elements disposed in a degradable matrix material, 
 a braided sheath around the one or more axial reinforcement elements, and one or more layers of an outer region around the braided sheath; 
 wherein the pin has an axial direction along its length, 
 wherein the one or more axial reinforcement elements comprises a flexible rod including fibers oriented in the axial direction extending from a first end region of the pin to an opposing end region, 
 wherein the fibers of the axial reinforcement elements include filaments formed of a degradable glass bound together by degradable material, 
 wherein the degradable matrix material includes a thermoplastic polymer, 
 wherein the sheath includes bias reinforcement elements, wherein the bias reinforcement element including fibers formed of a degradable glass, and 
 wherein the axial reinforcement element has a modulus of 6 GPa to 90 GPa and is included in an amount of 10 volume percent to 75 volume percent of the pin.